Doh for me, I should have researched a bit first. I take the easy access to answers on these message forums for granted sometimes.

If I understand this correctly, diffentials come in the following flavours with the following caveats:

Open - basically 1-wheel-drive. Easiest axle to route power to gets the power. In other words, if one wheel grips and the other doesn't, you're not going anywhere.

LSD - halfhearted attempted at 2-wheel-drive. Works fine until one wheel loses all grip, then all power is transferred to that wheel. In half-slipping conditions at least there's power to both.

Assisted "manual" locker - works like an open diff until it's locked, then power is split 50/50 to both axles.

Mechanical "automatic" locker - works like an LSD, but doesn't give up so easily. It "lets go" for turning, but otherwise is always 50/50. (side question, what happens if one wheel has 0 traction?)

Locked - always 50/50, period, end of story.

If this is right, wouldn't the mechanical diff be the best? No need to engage it, it legs go for turning, etc..

Thanks for taking time to answer, I figure there must be other people here with the same types of questions.